[Distribution of microorganisms lysing Pseudomonas aeruginosa in reservoirs and soil]

Various natural habitats were found to contain microorganisms producing lytic spots around their own colonies when grown on a lawn of viable Pseudomonas aeruginosa cells at 29 and 45 degrees C. The incidence of such microorganisms in water and soil was studied in quantitative terms. Contaminated waters with predominating Gram-negative heterotrophs and a high number of pseudomonades were shown to be an optimal source for the isolation of microorganisms causing the lysis of P. aeruginosa growing at 29 degrees C. Microorganisms responsible for the lysis of P. aeruginosa at 45 degrees C are abundant in the soil of mixed and foliage forests.